Recent years have seen the significant technical development in digital video apparatuses, and increasing chances for compression-coding a video signal (a plurality of moving pictures arranged in time series) and recording the video signal onto recording media such as DVDs and hard disks or distributing the video signal on the Internet. For example, the H.264/AVC (MPEG-4 AVC) is one of the standards for compression-coding a video signal. Furthermore, the High Efficiency Video Coding (HEVC) standard is currently being studied as a next-generation standard.
The HEVC standard (NPL 1) currently being studied includes a syntax called cu_qp_delta. Here, cu_qp_delta is a syntax indicating a delta value between two quantization parameters to be used in quantizing moving picture coding processes and moving picture decoding processes. In the quantization, a quantization parameter is changed according to cu_qp_delta, and the quantization is performed according to the changed quantization parameter.
The delta value of cu_qp_delta between the two quantization parameters includes sign_flag (cu_qp_delta_sign, sign bit) and cu_qp_delta_abs. Here, sign_flag is a sign (parameter indicating positive or negative). Furthermore, cu_qp_delta_abs includes significant_flag indicating whether cu_qp_delta is 0 or not, and minus1 indicating an absolute value.